In recent years, vehicle switches mounted on door portions of an automobile to detect opening/closing of doors and to control, for example, turning-on of lighting in a vehicle have been developed. FIG. 6 is a sectional view of a conventional vehicle switch. FIG. 7 is an exploded perspective view of the conventional vehicle switch. Operation body 2 having operation portion 2A on the upper part thereof is housed movably up and down in case 1 having a substantially box-like shape with its upper surface opened. Operation body 2 and case 1 are both made of insulating resin.
Fixed contact 3 made of metal is attached to the right side surface in FIG. 6 inside case 1. A lower end of fixed contact 3 protrudes to the lower part of case 1.
Mounting plate 4 includes opening 4A, through hole 4B, mounting portion 4C, edge portion 4D, contact portion 4E, and a plurality of engagement portions 4F. Mounting plate 4 has an elliptical shape seen from the upper surface, and is made of metal. Mounting plate 4 is provided with opening 4A on the right side in FIG. 6. Mounting plate 4 is provided with flat mounting portion 4C on the left side thereof. Through hole 4B is formed in the left part of mounting portion 4C. Edge portion 4D is formed on a section that is higher by one step than the outer periphery of mounting portion 4C.
Contact portion 4E bent downward and extending toward the inside surface of case 1 is formed on a section that faces opening 4A of mounting plate 4 (that is, on the left inside of opening 4A). A plurality of engagement portions 4F are formed on a section of opening 4A in which contact portion 4E is not formed. Convex-shaped locking portion 1A formed on the inner side of case 1 is engaged with contact portion 4E, and a plurality of convex-shaped locking portions 11A formed on the outer side of case 1 are engaged with the plurality of engagement portions 4F. Thus, case 1 is mounted on mounting plate 4.
A central part of U-shaped movable contact 5 is mounted on a lower surface of operation body 2. Movable contact 5 is brought into elastic contact with contact portion 4E of mounting plate 4 and fixed contact 3 in a state in which left and right ends of movable contact 5 are slightly flexed. Thus, a switch contact is formed. Movable contact 5 is formed of a metal thin plate.
Coil spring 6 is mounted in a slightly contracted state between the inner bottom surface of case 1 and the lower surface of operation body 2. Spring 6 urges operation body 2 and movable contact 5 upward.
Mounting plate 4 is insert-molded on the lower surface of cover 7 made of, for example, rubber. Operation portion 2A of operation body 2 protrudes upward from an opening on the upper surface of case 1. Dome portion 7A in the right part of cover 7 covers operation portion 2A. Hollow cylindrical portion 7B is provided in the left part of cover 7. Thus, vehicle switch 11 is configured.
A lower end of fixed contact 3 protruding toward the bottom surface of case 1 is coupled to a room lamp or the like by lead wire (not shown) or the like via an electronic circuit (not shown) of an automobile. Vehicle switch 11 is attached to a chassis (not shown) of a vehicle body by, for example, a screw (not shown) that is allowed to pass through hollow cylindrical portion 7B and through hole 4B, and mounting plate 4 is grounded to the chassis. Thus, vehicle switch 11 is mounted on a door portion of a vehicle.
In the above-mentioned configuration, when the door of the automobile is opened, operation body 2 is urged upward by spring 6, and left and right ends of movable contact 5 mounted on operation body 2 are brought into elastic contact with contact portion 4E and fixed contact 3, respectively. Thus, contact portion 4E and fixed contact 3 are electrically connected to each other via movable contact 5. The electronic circuit of an automobile detects the electric connection, and, for example, turns on the room lamp.
FIG. 8 is a sectional view of a conventional vehicle switch during pressing operation. When a door is closed, pressing body 8 attached to the door presses operation portion 2A via an upper part of dome portion 7A of cover 7. Then, dome portion 7A is elastically deformed, and operation body 2 is shifted downward inside case 1 while it contracts spring 6.
Then, a left end of movable contact 5 mounted on operation body 2 is apart from contact portion 4E of mounting plate 4 and is brought into elastic contact with a left inside surface of case 1. Thus, contact portion 4E and fixed contact 3 are electrically disconnected from each other. The electronic circuit detects the electric disconnection, and, for example, turns off the room lamp.
Note here that in a state in which the door is closed, in general, pressing body 8 stops at a position in which operation body 2 is separated upward from an upper surface of cover 7 with a predetermined space. Therefore, a tip end of operation portion 2A of operation body 2 protrudes from the upper end of case 1 by a predetermined length, and a predetermined clearance is given between lower end portion 2B of operation body 2 and an inner bottom surface of case 1.
That is to say, by opening and closing operations of the door, operation body 2 of vehicle switch 11 mounted on the door portion of the vehicle is pressed and operated, electric connection and disconnection of the switch contact including movable contact 5, contact portion 4E and fixed contact 3 are carried out. Then, the electronic circuit of the vehicle detects the electric connection and disconnection, and carries out various controls such as turning on and off of the room lamp.